[clang] [analyzer] Don't display the offset value in underflows (PR #98621)

[Balazs Benics via cfe-commits]

https://github.com/steakhal commented:

This makes sense.
I wonder if we could have something in between. I'm thinking of having the concrete offset as a separate note, instead of having it part of the primary message.
That way after BR selection, we would still deterministically pick the shortest parh, and also have the offset in the path notes.

I find this better than dropping the concrete offset you worked so hard acquiring. WDYT?

https://github.com/llvm/llvm-project/pull/98621